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1、 What is stainless steel precision casting

In the production of stainless steel products, some products have peculiar shapes and cannot be produced using bending technology. Using wax molds, sand molds, and liquid material filling molding processes to produce irregularly shaped (hollow or solid) products.

Advantages: Different products can be made according to different wax types

Disadvantages: The precision of the blank forming is not high, and the surface roughness is large.

2、 Precision casting process

1. Make molds according to different shapes of the product. The mold is divided into upper and lower molds, which are completed through comprehensive processes such as turning, planing, milling, etching, and electrical discharge. The shape and size of the pit are the same as half of the product. Due to the fact that wax molds are mainly used for industrial wax mold forming, aluminum alloys with low melting point, low hardness, low requirements, low price, and light weight are selected as molds.

2. A large number of industrial wax solid core models were produced using aluminum alloy molds. Under normal circumstances, solid wax models can only correspond to blank products.

3. In order to refine the edges of the wax mold, several individual wax molds are glued onto a pre prepared mold (also known as a group tree) after deburring. This mold is also an industrial wax solid core mold for wax mold production. (It looks like a tree)

4. Apply industrial adhesive to several wax molds fixed on the mold head, and evenly spray a layer of fine sand (a type of refractory sand, high temperature resistant, usually silica sand). The sand particles are fine, and the final rough surface can be as smooth as possible.

5. Air dry the wax mold sprayed with a layer of fine sand at a set room temperature (or constant temperature), without affecting the shape change of the internal wax mold. The natural drying time depends on the complexity of the product itself. The air drying time for precision castings is generally around 5-8 hours

6. After sandblasting and natural air drying, continue to use industrial adhesive (silicone slurry) on the surface of the wax mold and spray a second layer of sand. The particle size of the second layer of sand particles is larger and thicker than that of the layer of sand particles. After the second layer of sand is sprayed, the wax mold is naturally air dried at the set constant temperature.

7. After the second sandblasting and natural air drying, proceed with the third, fourth, and fifth sandblasting in sequence. Requirement: Adjust the sandblasting frequency according to the surface requirements, volume, and self weight of the product. Generally, the sandblasting frequency is 3-7 times. -The size of sand particles changes over time. Usually, the sand particles in the later stage are thicker than those in the previous process, and the drying time is also different. In general, the complete production cycle of wax mold sand is about 3-4 days.

8. Apply white industrial latex (silicone oil slurry) on the wax mold that has completed the sandblasting process before baking, bond and solidify the sand mold, seal the wax mold, and prepare for later baking. Meanwhile, after the roasting process, the brittleness of the sand mold can be improved, making the sand layer easy to break and removing the blank.

9. The wax mold is fixed on the mold head during the baking process, completing sandblasting and air drying processes, and heated in a metal sealed special oven (usually a kerosene burning steam oven). Due to the low melting point of industrial wax, with a temperature of around 150 ℃, the wax mold melts when heated, forming wax water that flows out along the sprue for dewaxing. The wax mold after dewaxing is just an empty sand shell. The key to precision casting is to use this type of empty sand shell. Generally speaking, this wax can be reused, but these waxes need to be filtered again. Otherwise, unclean wax will affect the surface quality of the billet, such as sand holes and pits on the surface, as well as the shrinkage rate of investment casting products.

10. In order to make the dewaxed sand shell stronger and more stable, the sand shell must be baked before pouring stainless steel water, usually in a high-temperature (about 1000) furnace.

11. After dewaxing, pour the stainless steel dissolved into liquid at high temperature into the sand shell. Fill the space of the original wax mold with liquid stainless steel water until it is completely filled, including the middle part of the mold head.

12. Due to the mixing of different components in water-soluble stainless steel boilers, the factory tests the percentage of materials. Then, explain according to the required proportions, such as adding these elements to achieve the expected effect.

13. After liquid stainless steel is cooled and solidified by water, the outer sand shell is crushed using mechanical tools or manual labor. Solid stainless steel products are in the shape of the original wax mold, which is the required final blank. Then cut, separate, and roughen them one by one to form a blank.

14. Blank inspection: The blank with sand holes and pores on the surface must be repaired by argon arc welding. To be honest, after cleaning up the garbage, it should be reheated.

15. Cleaning of raw materials: Qualified raw materials undergo a cleaning process.

16. Process other procedures until the final product is produced.